Selective heating apparatus

Claim 1

APPARATUS FOR LOCALIZED AREA HEATING OF WORKPIECES RESTINGLY CONTACTING ONE ANOTHER, AT LEAST ONE OF SAID WORKPIECES HAVING A LOW MELTING METAL COATING AT THE LOCALIZED AREA THEREOF, SAID APPARATUS COMPRISING: A SOURCE OF INFRA-RED ENERGY, AND HEAT DIRECTING MEANS INCLUDING A FOCUSING MEANS ADAPTED TO RECEIVE THE INFRA-RED ENERGY AND PROVIDE A CONCENTRATED BEAM OF DIMENSIONS COMMENSURATE WITH THOSE OF THE LOCALIZED AREA WHILE ABSTRUCTING TRANSMISSION OF INFRA-RED ENERGY OUTSIDE THE BEAM, SAID FOCUSING MEANS COMPRISING: A LENS SYSTEM FORMED FROM AN INTEGRAL BODY HAVING A FIRST TRUNCATED TRIANGULAR CROSS-SECTION PORTION HAVING A BASE AT ONE END THEREOF AND TWO CONVERGING SIDES, AN INTERMEDIARY SECOND RECTANGULAR CROSS-SECTION PORTION ADJACENT TO THE TRUNCATED END OF SAID RECTANGULAR CROSS-SECTION PORTION OF SAID BODY AND HAVING TWO OPPOSING PARALLEL SIDES EXTENDING FROM THE TWO CONVERGING SIDES OF SAID FIRST PORTION, AND A THIRD PORTION TERMINATING IN A FACE HAVING A PREDETERMINED CURVILINEAR SHAPE, SAID BODY BEING POSITIONED WITH RESPECT TO SAID INFRA-RED SOURCE SUCH THAT THE INFRARED ENERGY ENTERS THE BASE OF THE FIRST PORTION OF SAID BODY AND PASSES THROUGH SAID FIRST, SECOND AND THIRD PORTIONS OF SAID BODY AND EMANATES FROM THE FACE OF SAID THIRD PORTION, SOME OF SAID INFRA-RED ENERGY PASSING THROUGH SAID BODY BEING FOCUSED BY SAID FACE INTO A LINE OF CONCENTRATED THERMAL INTENSITY AND SOME OF SAID INFRA-RED ENERGY PASSING THROUGH SAID BODY BEING DIFFUSED BY SAID SECOND RECTANGULAR CROSSSECTIONAL PORTION OF SAID BODY TO PROVIDE A ZONE OF LESSER THERMAL INTENSITY ABOUT SAID CONCENTRATED LINE, SAID WORKPIECES BEING POSITIONERD WITH RESPECT TO THE FACE OF SAID BODY SO THAT SAID CONCENTRATED LINE OF THERMAL INTENSITY LIES SUBSTANTIALLY ON THE LOCALIZED AREA TO BE HEATED TO CAUSE THE METAL COATING TO REFLOW AND THEREBY EFFECT THE BONDING OF SAID WORKPIECES.